Metallic water containing tanks such as water heater tanks, include tank openings and fittings supported at the tank openings. One type of a fitting support is a metal pipe nipple or spud welded to the outside of the tank. The inside of the tank is glass lined to avoid rusting caused by the liquid contained in the tank. However, with standard tank treatment techniques, the removal of the glass lining at the tank openings exposes, albeit to a very minor extent, the spud directly to the liquid contents of the tank. Accordingly, this becomes the weak spot in the tank which rusts and then eventually results in tank leakage.
As will be appreciated, water heaters are not the only type of tanks that suffer from premature rusting and leakage damage as described above.